Many log homes have wrap around decks, verandas, large windows and large open spaces. These spaces are as much of the living area as the cabin itself, and can add a lot of living space without a large cost.
If you are using your log cabin as your primary residence you will need to add some details that may not be required for a summer log cabin at the lake. Remember that new designs of log cabins can incorporate everything that houses have, so you have a lot of choices.